Conventionally, molded articles with inserts have been produced by disposing an insert within a mold cavity such that a portion of the insert having irregularities or discontinuities therein is covered with the molded material while a portion of the insert is isolated from the molding process by extending through a cavity in the mold wall. The molded article is thus attached to the insert by the configuration of the discontinuity in the insert such that a gripping relationship is achieved between the plastic mass and the insert. Examples of such techniques are described in U.S. Pat. No. 3,742,995 and U.S. Pat. No. 3,705,931.
The forming of molded objects having windows therein has presented a particular problem to the art. One process utilizing a molded foam plastic comprises the step of pressing an area of the molded form at an elevated temperature to collapse the plastic foam at the point of pressing to reform that plastic into a thin film which is transparent. A process of this type is described in U.S. Pat. No. 3,432,380. Window type inserts have also been included in molded plastic articles by first forming the article by conventional techniques and then physically cutting a portion of that article to provide an opening over which a window can be placed. Generally, the window will comprise either a transparent acrylic sheet or a glass sheet which is attached to the molded plastic article by means of an adhesive or some other appropriate means.
The mounting of mirrors, particularly automobile mirrors, has long presented a problem to the art. Conventionally, such mirrors have been mounted in metal frames which are mechanically tightened to grip the mirror and retain it in a desired position. The metal housing portion of this article serves the further purpose of providing a means of connecting the mirror to some other appropriately positioned support. The likelihood of breakage and general deficiencies of such an arrangement are readily apparent. An improvement upon the use of a metal housing is described in German Pat. No. 2,256,974. In accordance with this German patent, an automobile mirror is provided with a plastic edge molding which extends about the perimeter of the mirror. The mirror with the molding is thus inserted into a mold wherein the hollow area above the back of the mirror encompassed by the molding is filled with a foamable plastic which bonds with the molding. The newly applied foamed plastic can additionally be provided with means for attaching the thus produced mirror assembly to a predetermined support. The improvement in mirror protection and housing provided by this technique is readily apparent. While the use of a molded plastic housing provides protection for the mounted mirror, it suffers from the disadvantage of high product losses during the forming step wherein the glass mirror is contacted with the plastic in the viscous state under pressurized conditions.
Plastic housings for mirrors and other glass components have been provided from injection molded components which are assembled in much the same manner as are metal components.